Glycogen-rich clear cell carcinoma of the feline mammary gland: case report / Carcinoma de células claras rico em glicogênio da glândula mamária felina: relato de caso

The aim of this report is to describe the first histopathological, immunohistochemical, and clinical characteristics of a feline glycogen-rich clear cell carcinoma (GRCCC). A Persian queen was admitted with mammary gland tumors and underwent radical unilateral mastectomy. Overall survival was considered 33 days and death was due to clinical evolution of the disease. Microscopic evaluation demonstrated epithelial cells arranged in a predominantly solid pattern, tumor cells presented an ample, granular, and foamy clear cytoplasm, and moderate cellular pleomorfism. The presence of cytoplasmatic glycogen was confirmed through diastase digestion followed by PAS staining. Histopathological and histochemical findings lead to the diagnosis of GRCCC with regional metastases.(AU)

O objetivo deste relato de caso é descrever as características clínicas, histopatológicas e imuno-histoquímicas do primeiro carcinoma mamário de células claras rico em glicogênio em felino. Uma gata persa foi atendida com tumores na glândula mamária e foi submetida à mastectomia radical unilateral. A sobrevida livre de doença foi considerada 33 dias, e o óbito foi devido à evolução da doença. A avaliação microscópica demonstrou células epiteliais arranjadas em um padrão predominantemente sólido, as células tumorais apresentaram um citoplasma claro, amplo, granular e espumoso e pleomorfismo celular moderado. A presença do glicogênio citoplasmático foi confirmada pela digestão pela diástase, seguida da coloração de PAS. Achados histopatológicos e histoquímicos levaram ao diagnóstico de carcinoma de células claras rico em glicogênio felino com metástase regional.(AU)

Vaginal clear cell carcinoma in a Japanese Black cow.

During artificial insemination of an 18-year-old female Japanese Black cow, a mass that was of a hen's egg size was found in the vagina. On necropsy, the firm mass, measuring approximately 3.5 × 3.5 × 3.0 cm, was located at the superior region of the vagina. The cut surface of the mass was gray-white in color with occasional necrotic or hemorrhagic areas. Histologically, the mass was composed of tumor cells arranged in solid nests of various sizes with an occasional tubular structure separated by a delicate fibrovascular stroma. The tumor cells had a hypochromatic nucleus and abundant, faintly eosinophilic cytoplasm. The tumor cells contained diastase-sensitive periodic acid-Schiff positive granules. Immunohistochemically, tumor cells were positive for cytokeratin AE1/AE3, CAM5.2 and carcinoembryonic antigen, but not for vimentin, p63, estrogen receptor-α, progesterone receptor, α-smooth muscle actin, neuron-specific enolase, S-100 protein and chromogranin A. On the basis of these findings, the tumor was diagnosed as a clear cell carcinoma of the vagina.

Cytologic features of clear cell adnexal carcinoma in 3 dogs.

BACKGROUND: Clear cell adnexal carcinoma is a rare cutaneous adnexal neoplasm without definitive apocrine, sebaceous, or follicular differentiation. Differential diagnoses include sebaceous carcinoma, liposarcoma, and balloon cell melanoma. Immunohistochemical analysis, with positive immunoreactivity for pancytokeratin and vimentin, aids in the diagnosis. Cytologic features of clear cell adnexal carcinoma have not been described previously. OBJECTIVE: The aim of this study was to describe cytologic features of canine clear cell adnexal carcinoma. METHODS: Fine-needle aspirates (FNA) obtained prior to biopsy of cutaneous neoplasms with a histologic diagnosis of clear cell adnexal carcinoma confirmed by immunohistochemical analysis were reviewed retrospectively. Slides prepared from FNA had been stained with modified Wright-Giemsa or automated aqueous Romanowsky stain. RESULTS: Of 20 neoplasms diagnosed as clear cell adnexal carcinoma in dogs, FNA of the mass had been performed in 3 cases. Cytologic features were similar and included high cellularity, marked cellular pleomorphism, loose arrangement of neoplastic cells, and a light blue to gray background resulting from streaming of cytoplasm from ruptured cells. Neoplastic cells were oval to polygonal to spindle-shaped with wispy cytoplasmic projections. Cytoplasmic eosinophilic stippling, globular deposits, or pink needle-shaped inclusions were noted. Criteria of malignancy included marked anisocytosis, anisokaryosis and anisonucleoleosis, multinucleation, karyomegaly, macronucleoli, and atypical mitotic figures. CONCLUSIONS: Clear cell adnexal carcinoma should be included in the cytologic differential diagnosis for a canine cutaneous mass even if an epithelial origin is not readily identified owing to lack of characteristic epithelial features, such as highly cohesive cell clusters, evident cell-to-cell junctions, and distinct cytoplasmic edges.

Canine pancreatic clear acinar cell carcinoma showing an unusual mucinous differentiation.

A small solitary pancreatic nodule was identified in a 10-year-old mixed breed male dog. Microscopically, the lesion consisted of neoplastic clear acinar cells with diffuse, marked mucin production. Immunohistochemical and ultrastructural investigations confirmed the exocrine acinar origin of the tumour. The tumour was classified as a pancreatic clear acinar cell carcinoma (ACC) showing an unusual mucinous differentiation.

Canine cutaneous clear cell adnexal carcinoma: histopathology, immunohistochemistry, and biologic behavior of 26 cases.

Thirty tumors including 27 distinctive cutaneous neoplasms and 3 metastatic tumors from 26 dogs were collected from diagnostic submissions to 3 laboratories. Characteristic histopathologic features included location in the subcutis or dermis (or both); lobular, nodular, and nest-like architecture; and a component of epithelioid cells with clear cytoplasm. Additional features present in most cases included follicular dermal papilla-like structures, low mitotic index, nuclear pleomorphism, necrosis, and mineralization. Cytoplasmic periodic acid Schiff-positivity, which was abolished by pretreatment with diastase, indicated the presence of glycogen in all cases. The oil red O stain did not demonstrate cytoplasmic lipid. Melanin granules, accentuated by the Fontana-Masson method, were observed infrequently. A sparsely cellular mucinous stroma and stromal cartilaginous differentiation were uncommon. By immunohistochemistry, neoplastic cells stained positively for cytokeratin (29 of 29), vimentin (28 of 28), S-100 protein (24 of 29), and melan A (8 of 12); results were negative for smooth muscle actin and calponin in all cases. Clinical follow-up information was obtained on all 26 dogs. One tumor recurred, 1 metastasized to a regional lymph node, and 1 metastasized to regional lymph nodes twice. In another case, possible pulmonary metastasis was noted radiographically. The findings are consistent with a poorly differentiated, low-grade, adnexal carcinoma of the skin. Similar canine cutaneous neoplasms have been reported as "clear-cell hidradenocarcinoma" and "follicular stem cell carcinoma." The authors propose the designation "cutaneous clear cell adnexal carcinoma."

Thyroid c-cell carcinoma in an African pygmy hedgehog (Atelerix albiventris).

A 3-yr-old African pygmy hedgehog (Atelerix albiventris) was submitted with dysphagia, weight loss, and tetraparesis. A palpable mass was found on the ventral neck. Histologic examination revealed replacement of the thyroid gland by a highly cellular, expansile, and infiltrative mass composed of lobules of polygonal cells separated by fine fibrovascular septa. Examination of ultrathin sections revealed tumor cells with few to many dense-core neuroendocrine granules, approximately 100-200 nm in diameter, and stromal amyloid. Immunohistochemical stains were positive for neuron-specific enolase. Only rare cells had positive immunohistochemical staining for calcitonin. Findings are consistent with a neuroendocrine tumor of C-cell origin. This is the first report of a C-cell carcinoma in a hedgehog.